Generation of Hybridomas: Permanent Cell Lines Secreting Monoclonal Antibodies

Production of monoclonal antibodies involves in vivo or in vitro procedures or combinations thereof. Before production of antibodies by either method, hybrid cells that will produce the antibodies are generated. The steps in producing those cells are outlined below (figure 1). The generation of mAb-producing cells requires the use of animals, usually mice. The procedure yields a cell line capable of producing one type of antibody protein for a long period. A tumor from this “immortal ” cell line is called a hybridoma. No method of generating a hybridoma that avoids the use of animals has been found. Recent in vitro techniques allow the intracellular production of antigen-binding antibody fragments, but such techniques are still experimental and have an uncertain yield, efficacy, and antibody function (Frenken and others 1998). It has also been possible to genetically replace much of the mouse mAb-producing genes with human sequences, reducing the immunogenicity of mAb destined for clinical use in humans. Before the advent of the hybridoma method, investigators could produce only polyclonal serum antibodies; this required large numbers of immunized animals and did not immortalize the antibody-producing cells, so it required repeated animal use to obtain more antibodies. Development of the hybridoma technology has reduced the number of animals (mice, rabbits, and so on) required to produce a given antibody but with a decrease in animal welfare when the ascites method is used